When Erin McMenamin turned up dead in Mare of Easttown’s premiere, it seemed like there were more suspects than residents in Mare’s small, sleepy town. But by the series’ penultimate episode, it seemed likely the killer was one of the two Ross brothers. But with all the focus on the men of the family, fans (and Mare) almost missed who Erin’s real killer on Mare Of Easttown was.
Warning: The big spoiler from Mare of Easttown’s finale episode follows. As viewers suspected, John took Billy to the cabin in order to kill him and stage it as suicide. Billy wasn’t DJ’s father; John was. (Turns out, DJ stands for “Dylan John.”) And the mysterious photo fans were obsessing over? It was a pic of Erin in bed with John.
Mare arrived in time to save Billy’s life. And when John tried to turn the gun on himself, Billy tackled him. Then, John confessed to Erin’s murder. It lined up with the details of the case: He’d left the party, killed Erin, and then returned to drive Frank home to give himself an alibi. He said he then convinced Lori to lie for him and say Billy was the killer.
But something was off. John’s gun wasn’t a left-rifling Colt Detective Special. Moreover, Frank told Mare he and John had been singing and telling jokes on the drive. He couldn’t reconcile it with the idea that John had just committed murder.
And there was Sandra. Earlier, Lori threw John out of the house because she believed he was having an affair with Sandra after Ryan’s breakdown at school. (The last time Ryan acted out like that was when he’d previously discovered his father’s affair.) But when Mare ran into Sandra, she learned they hadn’t been seeing each other.
Then Mr. Carroll called. He was wrestling with Betty’s death and had a sense things were disappearing from the house — random items: kitchen utensils, cups... and his gun, a Colt Detective Special.
Carroll said the gun had disappeared the night of Erin’s murder but then reappeared, missing a couple of cartridges. When Mare asked who knew about the weapon, the answer was himself and the kid who mows his lawn: Ryan Ross.
When Mare arrived at Ryan’s school, the boy took one look at her and ran home. That’s where Mare found him, sobbing in Lori’s arms. And that’s when it became clear: Lori hadn’t covered up for John. She’d lied for her son.
Turns out, Ryan had discovered his father was having an affair with Erin months ago and, not knowing about DJ, demanded he end it. When Erin started texting John at Frank’s party, Ryan saw and assumed his father had lied about calling it off. So, Ryan stole John’s phone and texted Erin to meet him at the park. He took Mr. Carroll’s gun from the shed, planning to scare her into leaving his family alone. Instead, she’d run at him, and in the scuffle, the gun went off.
As John got Frank home, Ryan called him, begging for help. John swore his son to silence, then rounded up Billy without telling him what happened. It wasn’t until the morning Mare followed John and Billy to the cabin that Lori learned what really happened. She’d have carried her son’s secret to the grave had Mare not discovered the truth.
As Mare put the kid into the squad car, she could barely keep from crying. And then there was Lori, who was in hysterical collapse. Why hadn’t Mare just come to her? John was serving the time; the case was closed. Mare had destroyed her family, and Lori never wanted to see her again.
But the best friendships can survive anything, including grief. It took months before Lori let Mare back into her life. The show ended with Mare in Lori’s kitchen, holding her BFF as Lori cried it all out, the women bound together by the loss of their sons.